assign.cc 10.2 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
#include <LEDA/graph_alg.h>
#include <LEDA/graphwin.h>
#include <LEDA/dictionary.h>
#include <LEDA/map.h>
#include <LEDA/graph_iterator.h>
#include <iostream.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/time.h>
#include <string.h>

#include "testbed.h"

16 17 18
#include "phys.h"
topology *topo = NULL;

19 20 21 22 23
/* How can we chop things up? */
#define PARTITION_BY_ANNEALING 0

int nparts = 3;     /* DEFAULTS */
int intercap = 2;
David G Andersen's avatar
David G Andersen committed
24
int *nodecap = NULL;
25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76
int better_heuristic = 0;
int accepts = 0;
int nnodes = 0;
int partition_mechanism;
int on_line = 0;

float sensitivity = .1;

static const int initial_temperature = 100;
static const int temp_prob = 130;

int refreshed = 0;

tbgraph G(1, 1);
node_array<int> bestnodes, absnodes;
float                       bestscore, absbest;

float *interlinks;
float *numnodes;

/*
 * Basic simulated annealing parameters:
 *
 * Make changes proportional to T
 * Accept worse solution with p = e^(change/Temperature*sensitivity)
 *
 */

inline int accept(float change, float temperature)
{
	float p;
	int r;

	if (change == 0) {
		p = 1000 * temperature / temp_prob;
	} else {
		p = expf(change/(temperature*sensitivity)) * 1000;
	}
	r = random() % 1000;
	if (r < p) {
		accepts++;
		return 1;
	}
	return 0;
}

float score()
{

	float sc = 0;

	for (int i = 0; i < nparts; i++) {
David G Andersen's avatar
David G Andersen committed
77
		/* Have we violated bandwidth between switches? */
78 79 80
		if (interlinks[i] > intercap) {
			sc += (interlinks[i]-intercap);
		}
David G Andersen's avatar
David G Andersen committed
81 82 83 84 85 86 87 88 89 90 91 92 93
		/* Do we have too many nodes per switch? */
		if (numnodes[i] > nodecap[i]) {
			sc += (numnodes[i] - nodecap[i]);
		}
		/* Try to minimize the number of switches used */
		/* This is likely NOT an effective way to do it! */
		if (numnodes[i] > 0) {
			sc += .1;
		}
		/* Try to minimize the bandwidth used... also probably
		   not effective */
		if (interlinks[i] > 0) {
			sc += .1 * interlinks[i];
94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257
		}
	}
	return sc;
}

void screset() {
	edge e;
	node n;
	for (int i = 0; i < nparts; i++) {
		interlinks[i] = numnodes[i] = 0;
	}
    
	forall_nodes(n, G) {
		numnodes[G[n].partition()]++;
	}
	forall_edges(e, G) {
		node v = G.source(e);
		node w = G.target(e);
	
		if (G[v].partition() != G[w].partition()) {
			interlinks[G[v].partition()]++;
			interlinks[G[w].partition()]++;
		}
	}
}

void scupdate(node n, int newpos)
{
	int prevpos;

	AdjIt it(G, n);
	prevpos = G[n].partition();
	if (newpos == prevpos) return;

	numnodes[prevpos]--;
	numnodes[newpos]++;

	while (it.eol() == false) {
		edge e = it.get_edge();
		node n1 = G.source(e);
		node n2 = G.target(e);
		/* Ensure that n2 points to the stationary node */
		if (n2 == n) n2 = n1;

		/* They were not in the same bucket to start with */
		/* So both contributed to their interlinks */
		if (G[n2].partition() != prevpos) {
			interlinks[prevpos]--;

			/* If they're together now, there's no interlink */
			if (G[n2].partition() == newpos) {
				interlinks[G[n2].partition()]--;
			} else { /* Otherwise, move the interlink */
				interlinks[newpos]++;
			}
		}
		else /* They were in the same bucket.  They aren't anymore,
		      * or we would have exited earlier */
		{
			interlinks[G[n2].partition()]++;
			interlinks[newpos]++;
		}
		++it;
	}

	G[n].partition(newpos);
}

int assign()
{
	float newscore, bestscore, absbest;
	node n;
	int iters = 0;

	float timestart = used_time();
	float timeend;
	float scorediff;

	nnodes = G.number_of_nodes();
 
	float cycles = 120.0*(float)(nnodes + G.number_of_edges());

	int mintrans = (int)cycles;
	int trans;
	int naccepts = 40*nnodes;
	int accepts = 0;
	int oldpos;

	float temp = initial_temperature;
  
	/* Set up the initial counts */
	screset();

	bestscore = score();
	absbest = bestscore;

	if (bestscore == 0) {
#ifdef VERBOSE
		cout << "Problem started optimal\n";
#endif
		return 1;
	}
  
	while (temp >= 2) {
#ifdef VERBOSE
		cout << "Temperature:  " << temp << endl;
#endif
		trans = 0;
		accepts = 0;
      
		while (trans < mintrans && accepts < naccepts) {
			int newpos;
			trans++;
			iters++;
			n = G.choose_node();
			oldpos = G[n].partition();

			newpos = oldpos;
			/* XXX:  Room for improvement. :-) */
			while (newpos == oldpos)
				newpos = random() % nparts;
			scupdate(n, newpos);
			newscore = score();
			if (newscore < 0.1f) {
				timeend = used_time(timestart);
				cout << "OPTIMAL (0.0) in "
				     << iters << " iters, "
				     << timeend << " seconds" << endl;
				return 1;
			}
			/* So it's negative if bad */
			scorediff = bestscore - newscore;

			if (newscore < bestscore || accept(scorediff, temp)) {
				bestnodes[n] = G[n].partition();
				bestscore = newscore;
				accepts++;
				if (newscore < absbest) {
					node n2;
					forall_nodes(n2, G) {
						absnodes[n2] = G[n2].partition();
					}
					absbest = newscore;
				}
			} else { /* Reject this change */
				scupdate(n, oldpos);
			}
		}
      
		temp *= .9;
	}
	forall_nodes(n, G) {
		bestnodes[n] = absnodes[n];
	}
	bestscore = absbest;

	forall_nodes(n, G) {
		G[n].partition(absnodes[n]);
	}
	timeend = used_time(timestart);
	cout << "   BEST SCORE:  " << score() << " in "
	     << iters << " iters and " << timeend << " seconds" << endl;
	cout << "With " << accepts << " accepts of increases\n";
	for (int i = 0; i < nparts; i++) {
David G Andersen's avatar
David G Andersen committed
258
		if (numnodes[i] > nodecap[i]) {
259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398
			cout << "node " << i << " has "
			     << numnodes[i] << " nodes" << endl;
		}
		if (interlinks[i] > intercap) {
			cout << "node " << i << " has "
			     << interlinks[i] << " links" << endl;
		}
	}
	if (score() < 0.0001) {
		return 1; /* Optimal enough */
	} else {
		return 0;
	}
}

void loopassign()
{
	node_array<int> nodestorage;
	int optimal = 0;
	int orig_nparts;
	int orig_cap;
	float timestart = used_time();
	float totaltime;

	nodestorage.init(G, 0);
	bestnodes.init(G, 0);
	absnodes.init(G, 0);
    
	nnodes = G.number_of_nodes();
	optimal = assign();
	totaltime = used_time(timestart);
	cout << "Total time to find solution "
	     << totaltime << " seconds" << endl;
}

void chopgraph(GraphWin& gw) {
	node n;
	forall_nodes(n, G) {
		G[n].partition(0);
	}
	switch(partition_mechanism) {
	case PARTITION_BY_ANNEALING:
		loopassign();
		break;
	default:
		cerr << "Unknown partition mechanism.  eeeek." << endl;
		exit(-1);
	}
}

void display_scc(GraphWin& gw)
{
	edge e;
	node n;
	
	if (!refreshed) {
		forall_nodes(n, G) {
			G[n].partition(0);
		}
		if (on_line)
			chopgraph(gw);
	}
	
	refreshed = 0;
	
	/* Now color them according to their partition */
	forall_nodes(n, G) {
		switch(G[n].partition()) {
		case 0:
			gw.set_color(n, black);
			break;
		case 1:
			gw.set_color(n, blue);
			break;
		case 2:
			gw.set_color(n, green);
			break;
		case 3:
			gw.set_color(n, red);
			break;
		case 4:
			gw.set_color(n, yellow);
			break;
		case 5:
			gw.set_color(n, violet);
			break;
		case 6:
			gw.set_color(n, cyan);
			break;
		case 7:
			gw.set_color(n, brown);
			break;
		case 8:
			gw.set_color(n, pink);
			break;
		case 9:
			gw.set_color(n, orange);
			break;
		case 10:
			gw.set_color(n, grey1);
			break;
		case 11:
			gw.set_color(n, grey3);
			break;
		}
	}
	
	forall_edges(e, G) {
		node v = G.source(e);
		node w = G.target(e);
		if (G[v].partition() == G[w].partition()) {
			gw.set_style(e, solid_edge);
		} else {
			gw.set_style(e, dashed_edge);
		}
	}
	gw.redraw();
}

void reassign(GraphWin& gw)
{
	node n;
	forall_nodes(n, G) {
		G[n].partition(0);
	}
	bestnodes.init(G, 0);
	absnodes.init(G, 0);
	chopgraph(gw);
	refreshed = 1;
	display_scc(gw);
}


void new_edge_handler(GraphWin& gw, edge)  { display_scc(gw); }
void del_edge_handler(GraphWin& gw)        { display_scc(gw); }
void new_node_handler(GraphWin& gw, node)  { display_scc(gw); }
void del_node_handler(GraphWin& gw)        { display_scc(gw); }

void usage() {
	fprintf(stderr,
399
		"usage:  assign [-h] [-ao] [-s <switches>] [-n nodes/switch] [-c cap] [file]\n"
400 401 402 403 404 405 406
		"           -h ...... brief help listing\n"
		"           -s #  ... number of switches in cluster\n"
		"           -n #  ... number of nodes per switch\n"
		"           -c #  ... inter-switch capacity (bw)\n"
		"                 (# of links which can go between switches\n"
		"           -a ...... Use simulated annealing (default)\n"
		"           -o ...... Update on-line (vs batch, default)\n"
407
		"           -t <file> Input topology desc. from <file>\n"
408 409 410 411 412 413 414 415
		);
}

int main(int argc, char **argv)
{
	int h_menu;
	extern char *optarg;
	extern int optind;
416
	char *topofile = NULL;
417 418 419 420 421
    
	int ch;

	partition_mechanism = PARTITION_BY_ANNEALING;
    
422
	while ((ch = getopt(argc, argv, "oas:n:c:t:h")) != -1)
423 424 425 426 427 428
		switch(ch) {
		case 'h': usage(); exit(0);
		case 's': nparts = atoi(optarg); break;
		case 'c': intercap = atoi(optarg); break;
		case 'a': partition_mechanism = PARTITION_BY_ANNEALING; break;
		case 'o': on_line = 1; break;
429
		case 't': topofile = optarg; break;
430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458
		default: usage(); exit(-1);
		}

	argc -= optind;
	argv += optind;
    
	interlinks = new float[nparts];
	numnodes = new float[nparts];
	for (int i = 0; i < nparts; i++) {
		interlinks[i] = 0;
		numnodes[i] = 0;
	}
    
	srandom(time(NULL) + getpid());
    
	GraphWin gw(G, "Flux Testbed:  Simulated Annealing");
    
	gw.set_init_graph_handler(del_edge_handler);
	gw.set_new_edge_handler(new_edge_handler);
	gw.set_del_edge_handler(del_edge_handler);
	gw.set_new_node_handler(new_node_handler);
	gw.set_del_node_handler(del_node_handler);
    
	gw.set_node_width(24);
	gw.set_node_height(24);
    
	if (argc == 1) {
		ifstream infile;
		infile.open(argv[0]);
459
		if (!infile || !infile.good()) {
460 461 462
		  cerr << "Error opening file: " << argv[0] << "\n";
		  exit(1);
		}
463 464 465 466
		parse_top(G, infile);
		gw.update_graph();
		node n;
		forall_nodes(n, G) {
David G Andersen's avatar
David G Andersen committed
467 468 469
			if (G[n].name() == NULL) {
				G[n].name("");
			}
470 471 472 473 474
			gw.set_label(n, G[n].name());
			gw.set_position(n,
					point(random() % 200, random() % 200));
		}
	}
475 476

	if (topofile != NULL) {
David G Andersen's avatar
David G Andersen committed
477
		cout << "Parsing phys\n";
478 479 480 481 482 483 484
		topo = parse_phys(topofile);
		if (!topo) {
			cerr << "Could not read in topofile "
			     << topofile << endl;
			exit(-1);
		}
		nparts = topo->switchcount;
David G Andersen's avatar
David G Andersen committed
485 486 487 488 489
		cout << "Nparts: " << nparts << endl;
		nodecap = new int[nparts];
		for (int i = 0; i < nparts; i++) {
			nodecap[i] = topo->switches[i]->numnodes();
		}
490
	}
491 492 493 494 495 496 497 498 499 500 501 502 503 504 505
    
	gw.display();
    
	gw.set_directed(false);
    
	gw.set_node_shape(circle_node);
	gw.set_node_label_type(user_label);
    
	h_menu = gw.get_menu("Layout");
	gw_add_simple_call(gw, reassign, "Reassign", h_menu);
    
	gw.edit();
    
	return 0;
}